1. Field of the Invention
This invention relates to railway signal mast assemblies, and in particular to a railway signal mast with a support platform for supporting a worker in close proximity to a railway signal light assembly supported on the signal mast.
2. Background & Description of the Related Art
Many railroad tracks, crossings and junctions are provided with masts for displaying signal lights or colorlites to communicate rail conditions and speed or movement restrictions to the locomotive engineer. Signal lights are commonly mounted in the viewing line of the locomotive engineer to accommodate easy viewing of the signal lights from the train. Historically, signal lights have been mounted on trackside vertical masts or on structures built over the tracks including on signal bridges or cantilevered masts. Signal lights mounted on trackside vertical masts are typically mounted starting at around 12 to 15 feet or higher above the track for easy viewing by the locomotive engineer. Although many railroads historically mounted trackside vertical masts on the right hand side of the track, many railroads have switched to bi-directional tracks. In order to accommodate this change, signal masts are installed not only on either the left or right hand side of the tracks in which they govern, but are also commonly equipped to signal trains approaching from either direction on the track.
Maintenance, repair or replacement of signal lights requires convenient access to the signal lights in order to quickly service the lights and avoid disrupting rail traffic. Access for maintenance, repair or replacement of the signal lights mounted on vertical trackside signal masts is commonly provided by a ladder and platform or series of platforms proximate each signal light. The ladder and platforms allow for an operator to service the signal lights and mast on location and while the signal lights are installed on the mast.
Prior art signal mast assemblies, comprising the mast, ladder, platforms, and other associated mast parts, are transported as separate pieces to the installation site. The parts are commonly transported by container or flatbed truck. Transporting the signal mast assemblies creates inefficiencies because the parts required to complete one assembly are often mixed with parts of other assemblies. Additionally, safety hazards to people moving about the parts can occur during shipping because various stacked parts may shift and become unstable during transport.
Assembly of the prior art signal masts commonly requires multiple workers, assistance of a lifting means such as a boom truck and more than an hour to complete the assembly. The mast is laid directly on the ground to begin assembly and workers use a boom truck lifting means to position the platforms, ladders, and other parts into place to be bolted or attached to the mast. As parts are bolted onto the mast, the weight and forces from the workers and attached parts may cause the mast to shift or rotate. Shifting of the assembly makes the assembly process more difficult; it also creates pinch points between the mast assembly and the ground where a body part may become trapped, pinched, or crushed. After assembly of the signal mast is completed, a lifting means is used to lift the assembly into place onto a foundation. The base of the signal mast is commonly bolted or secured onto the foundation for final installation. Prior art signal mast installations also commonly include a foundation to secure the mast ladder.
Because of the multiple parts required to assemble a signal mast, storage and transport of the signal masts is cumbersome; assembly and installation of the signal mast is time consuming. Few advances have been made to signal masts to address the challenges and hazards involved with the prior art. As a result of the shortcomings of the prior art, railroad representatives have expressed interest in signal mast towers having collapsible cages or that are otherwise easier to assemble and install.